Master class Biomolecular Sciences

Part 1: Molecular Cell Biology.

4 September 2007

Paul van Bergen en Henegouwen

Master class Biomolecular SciencesPart 1: Molecular Cell Biology. Sept-Nov 08

04-09-08: Paul van Bergen en Henegouwen. Mechanisms of clathrin-independent endocytosis

11-09-08: Willem Stoorvogel. Endocytosis and MHC classII

18-09-08: X-track symposium

25-09-08: Ger Strous. Ubiquitination and endocytosis 02-10-08: Catherine Rabouille (coordinator).

Classical and unconventional secretion09-10-08:Madelon Maurice. Wnt pathway and membrane traffic

16-10-08: ABC-seminar I&I +IB Aio dag

23-10-08: Fulvio Reggiori. Autophagy30-10-08: Bernd Helms. Lipid droplet biogenesis

06-11-08: Exam

Classical secretion

unconventional

Non clathrin mediated endocytosis

Before I start, few statements:http://www.bio.uu.nl/BiomolecularSciences/

- The course is compulsary. If you have no choice of missing ONE class, contact the teacher and the coordinator by email (on website)- Each lecture will be posted on the website few days after each class - Article presentation. Each of you will study one article per block in a group of 2-3-

4 persons. Prepare the article as well as possible while contacting the teacher at least one week in advance. When you meet, the

preparation should be done and you come for questions and for sorting out details.- Read the article: Download the article from the web for the colour pictures

before coming to the course using the guidelines, your brain and your knowledge. The more you have thought of it, the better the

discussion.- Exam. There will be 7 questions related to the 7 articles presented, hence

the above. The more you participate, the easiest.- Switch off your mobile. No ringing, no SMS.

Mechanisms of clathrin-independent internalization

Paul van Bergen en Henegouwen

Endocytosis: what’s the problem?

bending fission

Five ways to bend a membrane

Clathrin-dependent internalization

Clathrin-coated and vesicles:Ultrathin section of plastic-embedded material

Clathrin-coated pits and vesicles by EMReplica of freeze-dried plasma membranes

Clathrin-coated vesicles:Replica of freeze-dried plasma membranes

Clathrin: Heavy- and light chains

Clathrin makes a network

How clathrin is bending

Adaptor Protein-2 complex, AP-2

EarHinge

Trunk

100 kDa

50 kDa

17 kDa

-adaptin -adaptin

There are different AP-complexes on different sites in the cell

Golgi-complex Plasma membrane Golgi-complex

AP-1 AP-2 AP-3

Protein/protein interactions control CCV formation

Receptor

Yxx

Eps15

DPF

Receptor

LL

LxD/E

Clathrin

AP-2

I

EHs

II

COIL

III

DPF/UIM

Epsin

NPF

Lipids

DPW

PIP2

The netwerk forms a bal:Electron tomography of a coated vesicle

©John Wiley &Sons,Inc

Adaptor protein(AP2) complex

chain chain

adaptin adaptin

Clathrin triskelion

Smith et al. (1998) EMBO J. 17, 4943

Overview of clathrin structures

Marsh and McMahon (1999) Science 285, 215-220

From bending to fission

Dynamin, a GTPase involved in fission

PIP2 Amphiphysin

Dynamin is forming a ring around the neck

Effect of pure dynamin on lipid vesicles

PIPK

Membrane curvature generation

AP2ClathrinEps15

IntersectinAmphiphysinEpsin Dynamin

Endophilin

Moleculen involved in the whole process

Mogelijke rol van actine filamenten

PIPK

Membrane curvature generation

AP2ClathrinEps15

IntersectinAmphiphysinEpsin Dynamin

Endophilin

Actin

SynaptojaninAuxilinHsc70

Moleculen betrokken bij CCV vorming

Overview of all interactions

EGFR internalization via a non-coated pathway!

Is the alternative route visible?

Caveolae

Caveolin

Caveolar internalization starting from cholesterol-rich domains

Trafficking of Caveolae

Internalization of large items: Phagocytosis

Overview of different internalization routes

Properties of different CI-routes

Classification of internalization routes

Questions

What does the bending?What does the fission?

Interleukin-2 receptor complex

IL-2R internalization is Clathrin-independent clathrin-inhibition by ΔEps15

IL-2R internalization is Dynamin-dependentDynamin-inhibition by Dyn-K44

TfR

wt

K44A

IL-2R is present in the Detergent Resistant Membrane (DRM) fraction

Overview of different internalization routes